Deodorants are used together with an aromatizing agent to reduce uncomfortable odors or smells and, therefore, play an important role for comfortable human lives. Recent needs for deodorization are changing from aromatizing agents for masking malodors with a strong aroma to subtly-odorous or odorless deodorants capable of reducing or eliminating odors or smells themselves.
Also, there is an increasing tendency that clothes that are not in direct contact with the skin are repeatedly put on without immediate laundering. On the other hand, much care is taken about odors or smells from such clothes. Most of uncomfortable odors or smells encountered in the environment of human life are due to a composite odor. Therefore, it has been demanded to provide deodorants capable of effectively acting on such a composite odor.
Hitherto, there are known techniques for reducing or eliminating specific malodors. However, there are known few techniques that are effective to the composite odors or smells.
For example, JP 2001-40581A discloses a liquid deodorant using a cationic surfactant or an amphoteric surfactant in combination with a chelating agent for reducing or eliminating sweat smell or tobacco smell. JP 2001-70423A discloses a liquid deodorant using a deodorizing base agent such as perfumes in combination with a cationic surfactant and a specific solvent for reducing or eliminating sweat smell. However, these conventional liquid deodorants are unsatisfactory in deodorizing performance against aldehydes, etc.
JP 2001-178806A discloses a deodorant composition using a deodorizing base agent containing an extract obtained from plants as a main component, in combination with a perfume, ethanol and a surfactant for suppressing a rotten or putrid odor. JP 2004-176225A discloses a deodorizing fiber capable of reducing or eliminating ammonia smell, etc., which is treated with a treating agent composed of a betaine type amphoteric compound, a nonionic surfactant and an anionic surfactant. However, these conventional deodorizing products are also unsatisfactory in deodorizing performance against sweat small or aldehydes.
In JP 2004-49889A, it is described that an anionic surfactant containing a salt of at least one compound selected from the group consisting of triethanol amine, tris(hydroxymethyl)aminomethane, etc., is effective to suppress such a composite odor in which lower fatty acids and amines coexist. However, the anionic surfactant composed of such amine salts is insufficient in deodorizing effect on aldehydes and tends to exhibit a poor solubility in water, and is therefore unsuitable for preparation of deodorant compositions.
In JP 2001-95907A, it is described that an organic dibasic acid or a salt thereof is effective to deodorize lower fatty acids such as acetic acid and isovaleric acid, ammonia, amines such as trimethylamine, etc. However, the organic dibasic acid or the salt thereof is unsatisfactory in deodorizing effect on aldehydes.
In JP 2001-97838A, it is described that ethanolamine is effective to deodorize unsaturated aldehydes such as nonenal that is one of substances causing an aged smell from persons of middle or advanced age. However, the effect of ethanolamine on sweat smell, etc., is not clear, and further ethanolamine is stimulus and, therefore, unsuitable for use in such a configuration that the compound tends to be contacted with a human body.
JP 2003-533588A discloses a deodorizing composition containing cyclodextrin in which a primary amine compound is used as a buffer. However, in JP 2003-533588A, there is no description that a specific combined use of the primary amine compound and a nonionic compound exhibits a high deodorizing effect.
Under these circumstances, there is a demand for developing a deodorant which is not only capable of reducing or eliminating a composite odor derived from, especially, sweat smell and aldehydes, but also is safe to a human body.